Now that CPU cooler reviews have begun in earnest here at AnandTech, it's been interesting to see just how conventional wisdom plays out in practice. There's been a pervasive attitude that closed loop coolers are only really competitive with the highest end air coolers, and there may be some truth to that, but we have at least one of those flagship coolers on hand today along with parts from SilverStone, be quiet!, and Cooler Master.

Once we got in touch with Noctua and let them know we were doing cooler reviews, they gave us the opportunity to correct what I'd consider to be a sizable omission in terms of coverage in general: no review of the flagship NH-D14 CPU cooler. The NH-D14 is big, beefy, expensive, and typically regarded in enthusiast circles as one of the finest air coolers available. Alongside the NH-D14, Noctua also sent us their NH-L12 and NH-L9i low-profile CPU coolers; while the NH-L9i is potentially underwhelming, the NH-L12 stands to impress as potentially the most powerful downward-flow cooler on the market.

In the interests of making it a full-on roundup, three additional coolers were brought in for review. First is the flagship SilverStone Heligon HE01, a substantial dual tower cooler with a massive 140mm (38mm thick!) fan in the center and rated to cool a staggering 300W. Next up were two coolers I've had in house for a little while that are going to get to see sunlight and scrutiny: the be quiet! Dark Rock Pro 2 (rated for 220W) and the cooler from my case testing bed, the Cooler Master Hyper 212 EVO. The EVO can typically be found for under $40 (and usually much closer to $30) and is regarded as one of the best budget coolers on the market.

Before we get started with testing, some notes. First, the NH-D14 that Noctua sent is their Socket 2011 edition, but there's no appreciable difference between that one and the standard version; the mounting brackets from the NH-L12 were used for the NH-D14 and worked like a charm.

The be quiet! Dark Rock Pro 2 is unfortunately, like the rest of be quiet!'s line, still a bit rarefied stateside. That's unfortunate, because this little company has a lot to offer (as you'll see later). Of all the coolers tested, the Dark Rock Pro 2 is the most intimidatingly large, but be quiet!'s products are designed for silence first, so we'll see how it works out.

Finally, having the Cooler Master Hyper 212 EVO in this lineup almost seems unfair; it's smaller than the other coolers, only really benefits from one fan, and is the least expensive by a longshot. Looks can be deceiving, though. I used to run a Hyper 212 Plus and can attest to that cooler being both remarkably inexpensive and efficient, and the EVO's fan is both more powerful and quieter than its predecessor's.

I disagree. The coolers are measured under similar conditions and their performance in degress over ambient are listed. While seeing them in a real-world scenario might give you measurements that are more in line with a fully populated case, the variances introduced by the additional, unnecessary hardware might make it more difficult to get consistent, comparable results. I'm more concerned about relative performance and how coolers stack against one another and Anandtech's testing methods appear to be the best way to obtain those results without unreasonable expectations about controlled environment facilities.

Consistency and simplicity are good, but a procedure with a significant inherent bias is not (especially if this detail is not discussed by the reviewer... when it is not, it frankly seems like shortsightedness or incompetence, if not something worse). I rarely complain about testing procedures on most reputable review sites, but something is obviously flawed here. The results, which are out of line with most others', seem to indicate problems as well.

There is nothing much that similar about how the air coolers and CLCs are being tested. The air coolers are being tested inside a relatively restricted box. The side-blowing towers are blowing towards a metal wall with some puncture holes from where the fan should be (also note the offset between holes and cooler, exacerbated by using a miniITX motherboard with socket unusually low). The CLCs are being tested with radiators and fans actually up against the openings in the chassis.

Actually, for that matter, it would be good to know exactly the orientation and placement of the radiators and fans for how the CLCs were tested.

Anyway, if you want a simplified setup, something more fair would be to just use an open-air test bench or no chassis at all.Reply

An open air or open frame case might be a reasonable option. I hadn't really thought much about it and that's not a bad point. However, the net results -- the coolers in question all being tested in the same container -- would be the same. Honesty, Dustin could have stuffed all the hardware in a Tupperware container or a shoebox that used to have a pair of Nine & Co. Drama Print Peep-Toe Pumps in them and, as long as they were all under the same conditions, the result would be just as valid. Cooler effectiveness is a relative scale thing anyway since the conditions in which each person will use them are going to be unique to them. So many factors (room location, case exposure to sunlight, time of day, relative humidity, where you put your US Robotics ISA 28.8 data/fax modem, the number of Quantum BigFoot hard drives you have, etc.) impact a processor's operating tempratures that the testing methodology is trivial to the process of judging coolers as long as it remains consistent.

Atop that, Intel ships perfectly usable coolers with their boxed processors. While I enjoy the reviews, if I want a faster CPU, I'll invest the extra $100 on a next-model-up CPU instead of a pointlessly chromed-out cooler or I'll wait until a faster CPU is brought to market or I'll just do something else with my computer. Obviously that's a personal preference and others might feel differently, but in the grand scheme of things, only a few people can be bothered to even care about the difference between a CLC, an aftermarket air cooler, and something that came out of the box or was included in it when the OEM put it together.Reply

With regards to Intel's usable boxed cooler that's good enough for most people, I quite agree. However, they're not good enough for people who want to overclock significantly or want lower noise or temperatures or whatever; though the class of DIY builders who care about these things is small, they are relatively highly represented among AnandTech readers. Anyway, regardless of review subject material, if something's posted on AnandTech, it should be insightful and accurate, right?

As for the other paragraph, I think you're misunderstanding an important point here, maybe because nobody really stated it explicitly.

If you test different cooling designs in different test setups, the relative rankings will be different. That's why the test configuration is an important consideration. I'm not so concerned by the absolute numbers reported. Dustin used a test setup that very much does not represent what most people would be using, and this setup favors the CLCs over the air coolers. Someone not realizing this will read the results and think that CLCs have better performance relative to the air coolers than what you'd get in the real world in most case configurations. It's highly misleading.

Or at least, that's what I believe based on reading others' test results and based on my intuition on the subject. If Dustin could prove me wrong and alleviate these concerns by retesting just a couple coolers on a different setup, I would be very appreciative and would promptly tuck the tail between the legs and run off.Reply

"the testing methodology is trivial to the process of judging coolers as long as it remains consistent."

Is only true as long as the coolers being tested are fundamentally similar. What you're saying is akin to claiming it's ok to test a custom water loop against an air tower without hooking the water loop up to the CPU block because "the conditions are the same." How is it a fair comparison if you're denying one solution's access to the medium by which it cools?Reply

No, you are missing the issue. Yes, you can see relative performance, but because of the test flaw you can only compare the air coolers to each other (accurately) and the water coolers only to each other but you have to keep in mind that their fans bias even their results yielding advantage to the CLC with the most airflow added by its radiator fans.

To make it fair, you can possibly move the radiator outside the case and maybe run it in a hotbox that matches the test case interior.

Still, I think the only fair comparison is to add fans to the air coolers to match the radiator coolers as mentioned above. So you test CLC + radiator taking up vent space vs air cooler + extra fan taking up that same vent space.

So in practice I would expect this test to show that CLC are amazing and top performers. We see this. In fact the results made me look at the test method to see if the CLC were even allowed to reach equilibrium or not they seemed so skewed.

So good test for comparing only CLC to each other, or only AC to each other. Sucks for determining the true champions though because AC got shafted.Reply